A vehicle typically includes a climate control system which maintains a temperature within a passenger compartment of the vehicle at a comfortable level by providing heating, cooling, and ventilation. Comfort is maintained in the passenger compartment by an integrated mechanism referred to in the art as a heating, ventilation and air conditioning (HVAC) air-handling system. The air-handling system conditions air flowing therethrough and distributes the conditioned air throughout the passenger compartment.
The air-handling system commonly employs a housing having a plurality of passageways and doors for controlling a temperature and a flow of the air therethrough. The housing may for example be divided into an inlet section, a conditioning section, a mixing section, and a delivery section. The inlet section may include a blower or fan for delivering the air to the conditioning section. The conditioning section includes one or more heat exchangers for controlling a temperature and humidity of the air. Control features disposed within the conditioning section control the flow of the air through passageways having the heat exchangers disposed therein. For example, temperature doors, or otherwise referred to as flaps or valves, can be employed to control the flow of the air through passageways having the heat exchangers disposed therein. The mixing section is disposed downstream of the conditioning section and forms a chamber for recombining each of the streams of air, whether heated or cooled, exiting the conditioning section. The delivery section includes a plurality of conduits or ducts branching from the mixing section for delivering the air to desired vents located within the passenger compartment of the vehicle.
Generally, the air-handling system is adapted to control the air distributed to at least three zones of the passenger compartment. For example, the first zone may be a front driver side, the second zone may be a passenger driver side, and the third zone may be a rear occupant zone. The vents disposed within the passenger compartment may include panel vents, defrost vents, and front floor vents disposed in each of the first zone and the second zone. Additionally, the vents may include rear console and rear floor vents disposed in the third zone, for example. The delivery section is configured to deliver the air originating from the mixing section to any combination of the vents based on the operating mode selected by a passenger of the vehicle. Each operating mode includes a preselected percentage (or distribution ratio) of the air originating from the mixing section delivered to each of the corresponding vents associated with the selected operating mode. Doors disposed within the delivery section may be actuated to control the distribution of the air to each of the desired vents by blocking or opening various passageways disposed within the delivery section. For example, a “panel operating mode” may include the air distributed only to the panel vents and the rear console vents, a “defrost operating mode” may include the air distributed only to the defrost vents, and a “floor operating mode” may include the air distributed to each of the front floor vents, the rear floor vents, the windshield defrost vents, and the side window defrost vents. Other modes in which air is distributed among to other combination of the vents are also employed in many vehicles such as a “bi-level mode” or “mix mode.”
In certain vehicles, the doors disposed within the delivery section to control the distribution of the air to the vents in the first zone and second zone, for example, extend along a width of the housing from or proximate to a first side of the housing to or proximate to a second opposing side of the housing. These doors are controlled with a single actuator and kinematics system positioned externally to the housing at either the first side or second side of the housing. However, depending on the air handling system package requirements, vehicle space requirements, and sizing and configuration of the housing, a smaller door or auxiliary door may be required for controlling the distribution of air to the third zone. The smaller door is disposed at a distance from the first side and the second side of the housing respectively, and in certain applications may be centrally positioned with respect to the width of the housing and/or the doors providing distribution to the first zone and the second zone. Therefore, in known systems, the smaller door is not as easily and cost effectively mechanically linked to the single actuator and kinematics system.
For example, in order to mechanically link the smaller door to the single actuator and kinematics systems, some know systems use an external configuration which requires additional components to and enhancing the dimensions of the single actuator and kinematics systems included externally to the housing. Additional components needed to accommodate the smaller door or auxiliary door may be gear wheels, shafts, couplings, and larger housings for example. The additional components are costly and enhance the dimensions of the single actuator and kinematics system, add manufacturing and assembly complexity, and may not be feasible for achieving certain package and space requirements.
In order to avoid the complexity and infeasibility of the external configuration, an internal configuration is typically utilized within the housing. However, the internal configuration is not always feasible due to package and size requirements. If package and size requirements permit the utilization of the internal configuration, the internal configuration requires many components. These components occupy desired interior air flow cross-sectional areas which minimizes the performance of the air-handling system and complicate assembly of the air-handling system.
Furthermore, the position of the smaller door may depend on the position of the other doors. Therefore, there is a desire for increased precision between control of the positions of the doors relative to each other. The known external configurations and internal configurations may not provide the precision required which results in mechanical hysteresis between the doors and minimizes the desired performance of the air-handling system.
Accordingly, there exists a need in the art to simply, efficiently, and simultaneously control two or more doors of an air-handling system in a low cost manner, while maintaining desired package size requirements.